Ion-tuned DNA/Ag fluorescent nanoclusters as versatile logic device

摘要

A novel kind of versatile logic device has been constructed utilizing ion-tuned DNA/Ag fluorescent nanoclusters, with K~+ and H~+ as two inputs. A well-chosen hairpin DNA with a poly-C loop serves as the template for synthesizing two species of Ag nanoclusters. Several G-tracts and C-tracts on its two terminals enable the hairpin DNA to convert into the G-quadruplex and/or i-motif structures upon input of K~+ and H ~+. Such a structural change remarkably influences the spectral behaviors of Ag nanoclusters. In particular, different species of Ag nanoclusters have distinct fluorescence responses to the input of K~+ and H~+. These unique features of DNA/Ag nanoclusters enable multiple logic operations via multichannel fluorescence output, indicating the versatility as a molecular logic device. By altering the specific sequence of the hairpin DNA, more logic gates can be constructed utilizing Ag nanoclusters.